I've been playing around with this 40 card version for a little while now. Local rules dictate a minimum of 40 cards per deck in casual play, so these types of decks are pretty common and a lot of fun.
One could easily allow this to be played with simply more counterspells and card draws. I'd probably splash Crumbling Necropolis and Diabolic Tutor if I planned on making this into a "legal" deck by legacy 60-card standards.
I saw some pretty fun combos involving Splinter Twin + Myr Galvanizer and wanted to try and make it both a fun and fast theme deck. Unfortunately I was beaten to the concept by someone else (Red White and Blue A"myr"ica theme), but I think my format is a bit better and plays a much faster win just due to draw speed bonuses.
This deck revolves around heavy mana ramping with various Myr for a quick win with Myr Galvanizer + Splinter Twin + Mana Myr of any color to create N copies of Myr Galvanizer with Haste which will have N + 2 power/toughness.
If one can get an additional Iron Myr on the field (ST + MG + IM + Myr for untap), it also can create an infinite mana loop for Fireball. Obviously Fireball and other more aggressive spells could be played more frequently in a 60-card version of this deck.
Counterspell/Razor Barrier help immensely if you need to play more on the defensive against a control deck or against someone who plays counters in order to prevent the destruction of Splinter Twin/Myr Galvanizer during your turn. I'd only advise waiting for the mana to play Counterspell/Barrier only if there is a concern with opponent Counterspell cards, though, because it does cost additional mana and can drag a game out longer than it should.
Overall I've seen huge success with this deck and frequently manage a successful combo before turn six.
And for those wondering, I did create custom sleeve-backings for these cards featuring the American Flag and the head of a Myr.
